Question

我在Android上制作游戏，其中有一个图像，你必须拖动并移动它。然而，当我拖动它时，在拖动图像的路径上创建了几个图像。请查看我的代码和帮助

package com.saad.alien;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.RectF;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnTouchListener;

public class Game extends Activity implements OnTouchListener {

    CustomView Cview;
    float x, y, left = 0, top = 0, right = 0, bottom = 0;
    float dx, dy;
    Bitmap man;
    int done = 0;
    RectF rman = new RectF(50, 50, 150, 150);

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);

        Cview = new CustomView(this);
        Cview.setOnTouchListener(this);
        x = 50;
        y = 600;
        dx = dy = 0;

        man = BitmapFactory.decodeResource(getResources(), R.drawable.man);

        setContentView(Cview);
    }

    @Override
    protected void onPause() {
        // TODO Auto-generated method stub
        super.onPause();
        Cview.pause();
    }

    @Override
    protected void onResume() {
        // TODO Auto-generated method stub
        super.onResume();
        Cview.resume();
    }

    public boolean onTouch(View v, MotionEvent event) {
        // TODO Auto-generated method stub

        try {
            Thread.sleep(50);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        // x = event.getX();
        // y = event.getY();
        switch (event.getAction()) {

        case MotionEvent.ACTION_DOWN:
            dx = event.getX();
            dy = event.getY();
            float length = x + man.getWidth();
            float height = y + man.getHeight();
            if (dx > x && dx < length && dy > y && dy < height) {
                done = 1;
            }
            break;
        case MotionEvent.ACTION_MOVE:
            if (done == 1) {
                x = event.getX();
                y = event.getY();
            }
            break;
        case MotionEvent.ACTION_UP:
            if (done == 1) {
                x = event.getX();
                y = event.getY();
                done = 0;
            }
            break;
        }

        return true;
    }

    public class CustomView extends SurfaceView implements Runnable {

        SurfaceHolder ourHolder;
        Thread ourThread = null;
        boolean isRunning = false;

        public CustomView(Context context) {
            super(context);
            ourHolder = getHolder();
        }

        public void pause() {
            isRunning = false;
            while (true) {
                try {
                    ourThread.join();
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                break;
            }
            ourThread = null;
        }

        public void resume() {
            isRunning = true;
            ourThread = new Thread(this);
            ourThread.start();
        }

        public void run() {
            while (isRunning) {
                if (!ourHolder.getSurface().isValid())
                    continue;

                Canvas can = ourHolder.lockCanvas();
                left = x;
                right = (x + man.getWidth());
                top = y;
                bottom = (y + man.getHeight());
                rman.set(left, top, right, bottom);
                can.drawBitmap(man, null, rman, null);
                ourHolder.unlockCanvasAndPost(can);

            }

        }

    }

}

Answer 1

在绘制之前，您需要在每个帧上清除画布。

例如：

 Canvas.drawColor(Color.BLACK)

android canvas.drawbitmap（）图像不断重复

1 个答案: